The support when it comes to issues is outstanding! We had an issue with our SQL Server database which was impacting some functionality from one of the applications we were using, but nothing major; they just helped us troubleshoot what went wrong without any fuss or drama at all.
I would recommend them because their support team are very knowledgeable and responsive - they know exactly how to resolve your problems quickly and easily so you can get back to work as soon as possible. Nothing really - maybe that there aren't too many services out there like this where everything is covered under one service agreement? But then again, if you're happy with the service provided already then why change anything else?? You should definitely go for it! Our website now loads almost immediately compared to before we used to spend half an hour waiting while trying to figure things out ourselves!